The Sun newspaper has written to some users of its site telling them that their personal information has been stolen by a hacker.
The Murdoch-owned paper said that "some customer information from competitions and polls was breached". In a letter to those it fears are affected, it said that the information lost "could include name, address, date of birth, email and phone numbers". But no financial or password information was compromised, it insisted.
The Sun was the victim of one attack perpetrated by members of the online activist group Anonymous last month and said it believed that breach was the source of this loss of data. But Anonymous members yesterday denied responsibility for the attack, which was instead claimed by a lone hacker, known as "batteye".
News International, which has set up a paywall around some of its other newspaper websites, is known to be trying to foster a close relationship with the customers who sign up with it, in a bid to increase revenue through targeted offers, based on those customers' preferences and online behaviour.
A data breach such as this is likely to be a setback, since much of the success of that plan rests in consumers placing their trust with News International. A spokesman for the company said: "We take customer data extremely seriously and are working with the relevant authorities to resolve this matter. We are directly contacting any customer affected by this."
The paper said it has reported the breach to the Information Commissioner's office and that it has been assisting the police with inquiries. The data breach is so far related only to those who entered their names and contact details into competitions.